feat: 知乎支持（关键词、评论）

media_platform/zhihu/exception.py

@@ -0,0 +1,12 @@
+from httpx import RequestError
+
+
+class DataFetchError(RequestError):
+    """something error when fetch"""
+
+
+class IPBlockError(RequestError):
+    """fetch so fast that the server block us ip"""
+
+class ForbiddenError(RequestError):
+    """Forbidden"""